"I just thought if we had a bit more belief about us, we could have got something," the Blues boss said after the 1-0 defeat at St Andrew's.
"We had two or three good opportunities but you have to take them against side's like Liverpool.
"They had chance's too and Maik Taylor kept us in it with the penalty save.
"In the second half, with the goal they got just before the break gave them extra confidence.
"But overall it was a decent cup tie."